With over 60,000 posts and 350,000 comments on Neatorama, I can tell you this with absolute certainty: sarcastic and snarky comments actually have a deleterious effect. It discourages most commenters and encourages only the trolls.

That wasn't my intention (and I wasn't being sensitive, just trying to be silly), but negative comments like this don't contribute anything to a discussion and often discourage other people from posting positive comments.